Although mating surfaces of pairs of surfaces to be sealed, such as automotive engine head and block surfaces, appear to be smooth and flat, most frequently they are not sufficiently smooth to provide an effective seal. Accordingly, a gasket is required to be placed between said surfaces to provide an effective seal.
There are a wide variety of gasket designs which include, inter alia, metal gaskets, gaskets of fibrous materials, sandwich-type gaskets which combine a metallic core and compressible fiber-elastomer facing material laminated to the core, and so forth. As disclosed in U.S. Pat. No. 4,625,979, a wide variety of automotive gaskets are provided with sealing aids, such as elastomeric beads. Such beads are located on a face of the gasket by a number of processes. U.S. Pat. No. 4,659,410 describes a silk screening process for locating a sealing bead on a gasket face.
As disclosed in U.S. Pat. No. 4,140,323, such beads can be deposited in embossments to confine the beads when the gasket is subjected to compression. The beads provide a support for the embossment and thereby also enhance the gasket's effectiveness.
Of course, for such a bead to function most effectively, it must be accurately located within the embossments. In processes such as silk screening, therefore, it is necessary to accurately align the bead material as it is deposited in the embossment. This is both laborious and expensive. Even though great care is exercised, it is still difficult to maintain accurate alignment between the sealing bead and the embossment within which the bead is deposited.
Therefore, it would be advantageous to provide an improved method for assuring proper alignment of a deposited bead and an associated embossment.